In the majority of pistols, locking takes place by tilting and rotating the barrel with respect to the barrel slide. The resultant mass forces impair the handling and therefore the security of fire. This disadvantage does not occur in the case of locking by means of locking bodies which are generally circular-cylindrical rollers. Nevertheless, this type of locking has not found widespread use.
A pistol of the type in question is known from Great Britain Patent No. GB 668,117. The locking bodies disclosed in GB 668,117 are circular-cylindrical rollers which bear against planar boundary surfaces of the transverse groove and thereby transmit the reaction force of the barrel to the barrel slide in the event of a shot. Linear contact prevails between the planar boundary surfaces and the circular-cylindrical rollers. The linear contact generates a high surface pressure (referred to as Hertzian stress) in both parts. Linear contact also prevails between the rollers and the connecting link of the locking block. It has been demonstrated that this high local surface pressure on all three parts, but especially on the parts positioned within the transverse groove, results in deformations which may cause fracturing. A further difficulty in the case of the pistol according to GB 668,117 is that the rollers have a narrowing configuration, and therefore the contact line is shorter than the height of the rollers. This type of locking is therefore not suitable for large caliber cartridges or cartridges having high gas pressures.
It has indeed been attempted to harden the parts concerned in such a manner that they withstand high surface pressures. Local inductive hardening has not been tried and tested in this case because it is too complicated and is not reliable, and cracking may occur at the transition from the hardened zone into the unhardened zone. These disadvantages do not occur in the case of gas nitriding because of the limited hardness depth of approximately 0.35 mm, but with linear contact, deformation cannot be avoided in the unhardened zone located therebelow.
It is therefore an object of the invention to design the locking in a pistol of the type in question in such a manner that the above-described disadvantages do not occur. The peak values of the local surface pressure are intended to be reduced such that the pistol is also suitable for normal to large calibers and even for high-explosive munition.